The invention relates to a process for producing dunnage directly on the site of use.
Materials with low density and high volume are commonly used as packing materials to insulate goods being shipped from shock. Among the materials used are polystyrene "peanuts," cups and "worms," pellets of foam rubber foam, plastics and expanded polyurethane foam. Air cushioning material is generally preferred over the above types of dunnage because it is lighter in weight, can be supplied and dispensed in a controlled manner, particularly in roll form, and applied to the product to be shipped in sheet form. The sheet form of material is also easier to dispose than the individual pieces of plastic dunnage after the product is removed, and the sheet form of material can be rewound for further use or disposed of by deflation.
However, air cushioning material also presents a variety of problems, as large volumes of the material must be kept on hand, and due to the necessity of shipping this material from the producer, shipping costs can be considerable.
In order to overcome these problems, devices have been proposed to produce sealed air dunnage on site from plastic sheets. U.S. Pat. Nos. 5,188,691, 5,203,761, and 4,576,669 all propose devices for producing air filled dunnage, typically bubble wrap, from plastic sheets on an "on demand" basis.
U.S. Pat. No. 3,575,757 discloses a process for producing dunnage on site from plastic sheets in which opposed sheets are bonded together in a U-shaped seal to form a pocket, the pocket is inflated and then sealed by the formation of a subsequent U-shaped seal.
However, the above methods of producing dunnage are somewhat disadvantageous, as the apparatus necessary to handle two separate sheets of plastic is somewhat complex and difficult to operate. When used on site, it is typically operated by people whose expertise is not in the production of dunnage and who have some difficulty operating the equipment at peak efficiency.